New information about the habits of extinct whales may shed light on the behaviour of their modern relatives, writes Andrew Masterson.

An artist’s reconstruction of a mother and calf Parietobalaena yamaokai, an extinct species of baleen whale.

Nobumichi Tamura

A close second look at a fossil has revealed a previously unknown breeding ground for an extinct whale, and potentially sheds light on how species respond to changing climatic conditions.

In a paper published in the journal PeerJ, Cheng-Hsiu Tsai of the National Museum of Nature and Science, in Tsukuba, Japan, reports on a careful re-examination of several fossils of an extinct baleen whale, Parietobalaena yamaokai, that existed around 15 million years ago.

The fossils had hall been collected over the past century from around Hiroshima, and were held in that city’s Hiwa Museum for Natural History.

Examining one of the exhibits, part of a skull, Tsai noticed that two of the bones had not knitted together fully, indicating that the animal must have been under six months old when it died.